To adjust the brightness of mid-tones on your video image without affecting shadows and highlights
From the NVIDIA Control Panel navigation tree pane, under Video, click Adjust video color settings to open the page.
If applicable, select the display on which you are playing the video.
Under How do you make color adjustments, select With the NVIDIA settings.
Click the Gamma tab.
Move the Gamma slider or the individual Red, Green, and Blue sliders to increase or decrease the brightness of mid-tones on your video image without affecting shadows and highlights.
Click Apply when done.